The term “adaptive headlight system” is commonly applied to a system for a motor vehicle in which one or more lamps are controlled to generate and direct (or “steer”) projected light to selectively illuminate a portion or portions of a scene (visible to a vehicle driver) with varying levels of illumination. Such a selective and varying illumination of portions of the scene viewed by the driver is commonly referred to as “adaptive light distribution.”
DE 10 2012 002 333 A1 teaches a vehicle headlight system in which a light distribution contains at least one light beam which generates a limited illuminated area, similar to a spot-beam, in a predefined region in front of the vehicle. The light distribution can be composed of a plurality of different light beams to form a total light distribution. The light beams can be generated either by pivotable/steerable lighting modules or, such as if the light source is an LED array, by selectively switching the LED light sources on and off, wherein flashing effects can also be generated. A camera with image evaluation of the camera image such that a lane boundary and the position and profile thereof with respect to the vehicle are detected and are transmitted to a light control unit for the light distribution is located in the vehicle, said light control unit setting the light distribution in such a way that a lane boundary which is crossed by the vehicle is illuminated with higher illumination intensity than other regions of the field of vision.
DE 10 2010 046 517 A1 teaches a vehicle headlight system in which a lighting unit generates a specific light distribution which is sensed by an imaging sensing unit, wherein a horizontal and/or vertical light/dark boundary of the light distribution is determined by evaluating an image of the scene in front of the vehicle and is compared with reference values. In the case of deviations the lighting unit is adjusted automatically in order to avoid dazzling objects and other road users and to illuminate obstacles selectively by means of a hazard light. The type of the object is also determined, for example as vehicles, pedestrians, cyclists, animals, etc. Such a vehicle headlight system is also referred to as an automatic lighting assistant, which automatically adjusts the main beam on the basis of the moving and non-moving objects sensed in front of the vehicle. Sensed objects can be extracted from the light distribution, in particular with a “partial full-beam with defined interval”. Alternatively, individual objects can also be illuminated more strongly with what is referred to as a hazard light, the intention being to avoid dazzling, without any more detailed description as to how this could happen.
For the human eye it is a difficult task to detect objects such as, for example, pedestrians when driving at night, because the contrast sensitivity of the eye at night is lower than in daylight, and additionally because such objects frequently stand out from their surroundings only with small differences of brightness. Known automatic lighting assistants which direct a spot-beam onto the object in addition to the main beam, solve this problem by attracting the driver's attention to a critical object. However, visually detecting and precisely identifying the illuminated object may still be difficult for the driver owing to the low contrast sensitivity of the human eye and, in certain conditions, the lack of contrast at night. Furthermore, the illumination intensities of spot-beams are subject to legal limits owing to the risk of dazzling others (an on-coming driver or pedestrian, for example). Spot-beams, and, in particular, flashing effects can be misinterpreted by illuminated persons, which may increase the risk of an accident. There is also the risk of an accident if a dazzled animal stops when crossing the roadway.